Method of vulcanizing vulcanizable articles.



W. W. DUNCAN 61 N. E. TUSLEY.

METHOD 0F VULGANIZING vULcAZABLB ARTICLES. APPLICATIN FILED NOV. 17, 1910. REN

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EWED HAY 20, i912.

Patented, Den. 24, 1912.

narran sierras -rairnur ourson.

WILLIAM W. DUNRN, 0F BOSTON, AND NELSON E. TOUSLEY, OF W'ATERTOXVN, MAS- SACHUSETTS, .ASSIGNORS T0 HOOD RUBBER COMPANY, A CORPORATION OF MASSA- CHUSETTS.

METHOD OF VULCANIZING VULCANIZABLE ARTICLS.

ySpecification of 'Letters Patent.

Application filed November 17, 1910,`Seria1 `No. 592,927'. Renewed May 20, 1912. Serial No. 698,624.

which are made of rubber or rubber and fabric upon formers or lasts, such, for instance, asirubberl foot wear, and has for its object to shorten the vulcanizing period, re-

duce the cost, and, at the same time.. secure the production of durable high grade articlesfree from all blisters and defects.

The invention includes the novel method of procedure and the apparatus for carrying out said method hereinafter described and particularly defined in the appended claims. The apparatus ifor carrying out` said method' is illustrated in the accompanying drawings, in whicht Figure l is aside elevation; Fig. is a transverse section; and Fig. 3 1s a detail.

Referring by reference characters to this drawing, the numeral l designates a suit-` able chamber havingr a door 2 at one end designed to hermetically close the same. lVit-hinthe chamber at the bottomare rails 3 upon which travel the vvlfieels il of a truck 5 carrying racks 6 for thesupport of the formers or lasts. y

7 designates a steam supply pipe which is connected with any suitable source of steam under pressure, and is provided with a plurality of branches .7 connecting at diii'erent points with the interior of the chamber 1,

preferab y at the top thereof, and 8 designates an air supply pipe which is connected with any suitable source of heated air (not shown) designed to supply heated air under pressure to the chamber through the ybranch pipes 8a'. At the bottoni of the chamber are provided a plurality of outlets 9 leading to a main outlet pipe 10.A A large number of inlet branches are provided so that the steam and air may ber introduced at a large number of points at once into the interior of the vulcanizing chamber, and it is preferable to have a. plurality of outlets as shown,

though there need not be as many outlets as inlets. i

In order to operate the inlet pipes in unison witheach other and also the outlet pipes, it is preferable to provide diaphragm valves such as shown in detail in Fig. 3, in which the spring pressed valve stems ll are connected with expansible diaphragms l2 so arrangedthat by the admission of air or other motive fluid to a supply pipe common toall the yalves, these valves will be opened in `uvnison`an `amount dependent upon the pressure oramount of air admitted. A pipe 13 leads to the steam inlets, another pipe 14. to the air inlets, and a pipe `15 to the outlets, these pipes being controlled by valves 13, 14e and 15a, respectively.

Our improved method of operation in zvulcanizing goods with this apparatus is as follows, the pressures and temperatures stated being those found preferable: The goods, made and assembled upon the lasts or forms in the ordinary manner, and varnished with the regular or any suitable `varnish, are placed in the apparatus which is then hermetically closed. The air inlets are then opened .and` air heated to 280 F. is introduced until the pressure gage 16 indicates pounds pressure. Theair is retained in the chamber until the goods are heated to approximately 270 F. usually requires about forty-five minutes, during which timethe rubberis softened by the heat suiiiciently to allow all stretch to be removed, whereby all danger ol" subsequent cracking in the vulcanized article is avoided. The air supply isthen cut oit and the steam inlet pipes opened, supplyingr steam at about Patented Dec. 24,1912.

which 80 pounds pressure, and at the initial turning on oit' the steam, the outlet pipes are opened, allowing the steam to blow through to displace the air when, as soon as the air has been displaced, the outlets being closed, the goods are retained under dry steam at 'the pressure stated until vulcanization is complete. Justvprior tothe removal of the goods from the vulcanizer the steam supply is cut oit', the outlet opened and the air supply turned on again, allowing y'the heated air to blow through to displace the steam.

The initial heating of the goods under pressure and by' heated air preyents blistering of the goods and raises them to a sutil- Y cient temperature to prevent any condensation of steam thereon, and similarly the displacing of the steam by heated air before the vulcanizer is opened or the goods cooled prevents any final condensation of steam.

Having thus described our invention whff We claim is:

l. The hereindescribed method of treat` ing articles made of vulcanizable gums which consists in placing them in a hermetically closed chamber, supplying air under pressure to said chamber at a temperature such as to soften the rubber and remove the stretch, withdrawing the air and replacing it with steam under pressure, and

nally replacing the steam with heated air after vulcanization is complete for prevent: ing any final condensation of the steam upon the goods.

2. lThe hereindescribed method of`t1eating articles made of vulcanizable gums, which consists in placing them in a hermetically closed chamber, subjecting Ithem to heated air under pressure until the goods are raised to a temperature above that at which steam would condense thereon, replacing the air with steam under pressure, and at suiicient tel'nperature to complete the vulcanization of the goods, and finally dis placing the steam by previously -heated air .under pressure prior to re oval of the goods, substantially as deecib d.

3. The hereindescriibed method of treat ing articles made from vulcanizable gums which consists in placing them in a hernietically closed chamber, supplying air to said chamber at not less than 60 pounds pressure, and 270 E, replacing the air by steam at not less than 80 pounds pressure and subjecting the goods to the action of the steam until vulcanizat-on is complete, and nally replacing the steam with heated air, substantially as described.

'n testimony whereof, we aix'our signatures in presence of two witnesses,

' W'LLAM W.,DUNCAN.

ANELSON E. TOUSLEY 'Witnessesz J. B. More, E. E. ANDERSON. 

